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Biomedical subjects

K Ishigaki

Publications and source records attributed to K Ishigaki.

At least 19 recordsLinked to original sources

Video-assisted subtotal or near-total thyroidectomy for Graves' disease.

BACKGROUND: Surgery remains the treatment of choice for patients with Graves' disease. The purpose of the present study was to assess the usefulness and efficacy of video-assisted subtotal or near-total thyroidectomy in patients with Graves' disease. METHODS: Between March 2000 and December 2004, 63 patients with Graves' disease underwent video-assisted subtotal, near-total or total thyroidectomy. Fifty-three patients (84 per cent) were considered for surgery after failure of antithyroid drug and radioiodine therapy, whereas the other ten patients were initially selected for surgical treatment based on their own preference. Treatment outcome was evaluated, including surgical complications, thyroid function, quality of life and patient satisfaction with the surgical result. RESULTS: All patients were operated on using a video-assisted technique, with some modifications depending on time and experience. There were no conversions to open surgery. Three patients (5 per cent) had temporary recurrent laryngeal nerve palsy that recovered spontaneously. Most patients were satisfied with the surgical results, particularly regarding the placement of the surgical scars. CONCLUSION: Video-assisted subtotal or near-total thyroidectomy is a safe and effective procedure for treatment of Graves' disease.

Adolescent↗

Tie-2 and angiopoietin-1 expression in human thyroid tumors.

Tie-2 is an endothelial cell-specific receptor tyrosine kinase involved in vascular maturation and remodeling. Although its expression is considered to be restricted to vascular endothelial cells and hematopoietic progenitors, our immunohistochemical and in situ hybridization studies showed that Tie-2 and its ligand, angiopoietin (Ang)-l were expressed not only in benign and malignant human thyroid tumor cells but also in hyperplastic regions of adenomatous goiter. To confirm the expression in these tissues further, we used a laser capture microdissection system to isolate epithelial tumor cells from tissue specimens selectively, and demonstrated the expression of Tie-2 and Ang-1 mRNAs in tumor cells by RT-PCR analysis. Furthermore, Tie-2 and Ang-1 mRNAs and proteins were also detected in rat thyroid cell lines, FRTL-5 and PCCL-3. Our results suggest that Ang-1/Tie-2 signaling may be involved in the proliferation of thyroid epithelial cells.

Adenocarcinoma, Follicular↗

Urinary iodine levels and thyroid diseases in children; comparison between Nagasaki and Chernobyl.

We evaluated the incidence of childhood thyroid diseases and urinary iodine levels in Nagasaki, Japan and in Gomel, Belarus, which was greatly radio-contaminated by the Chernobyl accident, in order to obtain the comparative data of thyroid diseases between iodine-rich (Japan) and -deficient (Belarus) areas. In Nagasaki, the median level of urinary iodine, measured by ammonium persulfate digestion in microplate method, was 362.9 microg/L. In order to evaluate the geographical differences in Japan, other samples were collected in Hamamatsu and in South Kayabe, Hokkaido, where the median levels were 208.4 microg/L and 1015.5 microg/L, respectively. Furthermore, thyroid screening by ultrasound (US) in Nagasaki revealed only four cases that showed goiter (1.6%) and two cases (0.8%) that had cystic degeneration and single thyroid cyst. There was no evidence of thyroid nodule detected by US examination. In contrast, the median of urinary iodine level was 41.3 microg/L in Gomel. The incidences of goiter (13.6%) and echogenic abnormality (1.74%) in Gomel were much higher than in Nagasaki, suggesting the critical involvement of iodine deficiency in increased childhood thyroid abnormality around Chernobyl. Radioactive iodine released just after the Chernobyl accident may have influenced predominantly children residing in iodine-deficient areas. Our results suggest that management of thyroid screening for schoolchildren at ordinary times may be beneficial for monitoring the adverse effects of radioactive iodine from the standpoint of future prospective study.

Adolescent↗

Development of instruments to measure appraisal of care among Japanese family caregivers of the elderly.

The purpose of this study was to develop two instruments for the evaluation of positive and negative appraisal of care among family caregivers of elderly Japanese care recipients within the framework of caregiver adaptation. The positive appraisal of care instrument (PAC) includes domains of relationship satisfaction, role confidence, consequential gain, and normative fulfillment. The negative appraisal of care instrument (NAC) includes domains of role exhaustion, isolation, relationship difficulty, and symptom management difficulty. The PAC and NAC are self-administered questionnaires and were developed from data collected from 337 family caregivers of relatives aged 65 years and over who were using visiting nursing services from 21 organizations in multiple areas of Japan. Out of 87 items, 21 PAC items and 14 NAC items were selected based on content and construct validity and internal consistency examination. Results show evidence of validity and reliability for the PAC and NAC, although some NAC domains may benefit from further refinement. The PAC and NAC will be useful research tools for examining elder caregiving experience and evaluating nursing care for elders.

Activities of Daily Living↗

Appropriate method of administration of propofol, fentanyl, and ketamine for patient-controlled sedation and analgesia during extracorporeal shock-wave lithotripsy.

PURPOSE: The aim of this study was to identify the appropriate method for administering propofol, fentanyl, and ketamine (PFK) for patient-controlled sedation and analgesia (PCSA) during extracorporeal shock-wave lithotripsy (ESWL). METHODS: Twenty-one unpremedicated patients were randomly assigned to three groups that received different drug administration regimens. (group 1: low loading dose and high demand bolus, group 2: high loading dose and demand bolus, group 3: high loading dose and low demand bolus). RESULTS: The patients in all groups were hemodynamically stable during ESWL. Oxygen desaturation was recognized in all groups, but was avoided by 2 l.min(-1) of oxygen supply via a nasal prong. The total administration dose of the drugs was significantly higher ( P < 0.05) in group 2 than in groups 1 and 3. The median level of sedation was the same, but the episodes of oversedation were not recognized in group 3 ( P < 0.05). A significant difference in the frequency of episodes of oversedation was found between groups 2 and 3 ( P < 0.05). The results were good or excellent for almost all patients, and were assessed as fair by only one patient in group 2. CONCLUSION: We concluded that the method used for group 3 is the most appropriate for administering PFK for PCSA during ESWL.

Clinical Trial↗

A comparison between low-flow leak test and oxygen flush leak test.

PURPOSE: The clinical efficacy of two methods of preanesthetic leak test,namely the oxygen flush leak test (OFLT) and the low-flow leak test (LFLT), was compared regarding their ability to detect leakage in the anesthesia circuit and their accuracy. METHODS: Examinees comprised 16 staff anesthesiologists and 7 physicians undergoing anesthesia training at our institution. They performed the two leak tests on anesthesia machines with some intentional leaks (0.1-1.0 l.min(-1)). The leakage detection rates (LDR) were analyzed by the chi(2)-test. The ability to detect leaks was measured by recording how many leaks were detected by 50% (LDR(50)) and 95% (LDR(95)) of the examinees. RESULTS: The LDRs in the two tests were significantly different (chi(2)- analysis, P < 0.0001). Both LDR(50) and LDR(95) for the LFLT (0.23 and 0.41 l.min(-1), respectively) were smaller than the values for the OFLT (0.37 and 0.82 l.min(-1), respectively). The sensitivity and specificity of the LFLT (0.97 and 0.84, respectively) were higher than those of the OFLT (0.78 and 0.80, respectively). CONCLUSION: The LFLT was found to be superior to the OFLT regarding leak detection and reliability. We therefore recommend the LFLT for preanesthetic leak testing.

Journal Article↗

Sigmoid shape of the oxygen equilibrium curve and the P50 of human hemoglobin.

The fractional saturation of hemoglobin with oxygen was plotted against P/P50 and the slope of the abscissa at 1 was calculated for 38 OEC data sets of human Hb A. There was a linear correlation between the slope and the Hill coefficient (nmax), and the slope was about one-fourth that of nmax. This implies that the slope of the abscissa at 1 of Y vs P/P50 plot can provide information about the magnitude of cooperativity in hemoglobin oxygen binding.

Hemoglobins↗

Shape of the haemoglobin-oxygen equilibrium curve and oxygen transport efficiency.

The sigmoid shape of the oxygen equilibrium curve (OEC) of haemoglobin permits large changes in oxygen saturation (S) upon narrow variations of the partial pressure of oxygen (P). The slope of the Hill plot (n) calculated from the Adair constants for human adult haemoglobin is usually maximised at S values greater than 0.5, implying that co-operative interactions of haemoglobin subunits are maximised above half-saturation. Our analysis of OECs based on the Adair equation shows that the slope of the OEC, S', which is proportional to the capacitance coefficient beta (Piiper et al., Respir. Physiol. 13: 292-304, 1971) and is a direct measure for oxygen-transport efficiency of haemoglobin, is maximised at S values smaller than 0.5, usually at S = 0.38. The analysis also gives the relations: Pdmax < P50 < Pnmax and Sdmax < 0.5 < Snmax where Pdmax, P50 and Pnmax are P at which S' is maximised, P at half-saturation and P at which n is maximised, respectively, and Sdmax and Snmax are S at Pdmax and S at Pnmax, respectively. Thus the most efficient point of OEC does not coincide with the point of maximal cooperativity nor with the oxygen saturation level of mixed venous blood in resting conditions (S approximately = 0.75). The steep portion of the OEC around S = 0.38 is exploited for large oxygen demands under conditions of exercise. The most efficient oxygen unloading region around S = 0.38 could be revealed by the Adair analysis but not by analysis using the conventional Hill equation.

Adult↗

Relationships between the slope of the oxygen equilibrium curve and the cooperativity of hemoglobin as analyzed using a normalized oxygen pressure scale.

The oxygen equilibrium curve (OEC) for hemoglobin, which is usually expressed as a S vs. P plot, was expressed by normalizing P by Pdmax, where S is oxygen saturation, P is partial pressure of oxygen, and Pdmax is P at which the slope of the usual OEC is maximized. The maximal slope of normalized OEC gives Pdmax.S'max, where S'max is the maximal slope of the usual OEC, a measure for the oxygen transport efficiency of hemoglobin. Here, the term "efficiency" is used in the sense that the oxygen release from hemoglobin becomes more sensitive to oxygen pressure changes as S'max becomes larger. An analysis using 38 sets of published oxygen equilibrium data for human adult hemoglobin under various experimental conditions showed that (a) expressing OEC by means of S vs. P/Pdmax or S vs. log P is advantageous for analyzing the slope of OEC compared to usual S vs. P plot and (b) while the OEC differs depending on experimental conditions, S'max varies in close linear correlation to nmax (the maximal slope of the Hill plot which measures oxygen binding cooperativity), and Pdmax.S'max is almost equal to nmax/4. Thus, the parameter expressing oxygen transport efficiency is closely related to the parameter expressing oxygen binding cooperativity.

Adult↗

Glutathione concentration during maturation and after fertilization in pig oocytes: relevance to the ability of oocytes to form male pronucleus.

The present study examined the kinetics of glutathione (GSH) concentration during maturation and after fertilization in pig oocytes and its relevance to the ability of pig oocytes to form a male pronucleus after in vitro fertilization. The GSH concentration was significantly higher in pig oocytes matured in Waymouth medium than in pig oocytes matured in either modified (m) TCM-199 or mTLP media. The addition of 0.04-0.57 mM cysteine (CySH) to mTLP significantly increased both the GSH concentrations in oocytes matured in vitro and the rate of male pronucleus formation as compared to those in oocytes cultured in mTLP alone. When pig oocytes were cultured 12, 24, or 36 h in mTLP plus 0.14 mM CySH, their GSH concentrations were significantly higher than in uncultured oocytes. After fertilization, the GSH concentration in pig oocytes declined significantly. GSH concentrations in oocytes matured in vivo did not differ from those in oocytes matured in mTLP plus 0.14 or 0.57 mM CySH. The results indicate that 1) the composition of maturation medium affects the GSH concentration in pig oocytes; 2) the addition of CySH to maturation medium permits GSH synthesis by the pig oocytes; 3) GSH levels in pig oocytes change during maturation and after fertilization; and 4) GSH synthesis during oocyte maturation is an important factor for promoting their ability to form a male pronucleus after fertilization.

Animals↗

Assessment study on the high-performance liquid chromatography-type hydroxyapatite chromatography in the presence of sodium dodecyl sulfate.

The HPLC-type hydroxyapatite chromatography in the presence of sodium dodecyl sulfate (SDS) was assessed with special attention to the behavior of the surfactant. A significant amount of SDS was found to be adsorbed to the hydroxyapatite packed in the column from the starting buffer, 50 mM sodium phosphate buffer, pH 7.0, only when the buffer contained SDS in a concentration at or above its critical micelle concentration. When the phosphate buffer concentration was increased while the SDS concentration was kept at 1 mg/ml, the adsorbed surfactant was desorbed in advance of the release of proteins. Polypeptides derived from proteins could be successfully separated only when the column had been thoroughly equilibrated with the above-mentioned starting buffer solution. When a protein polypeptide complexed with SDS, which had been similarly equilibrated, was applied to the column, an amount of SDS corresponding to 75-90% (w/w) of the surfactant originally bound to the polypeptide was released upon its binding to the hydroxyapatite. On the other hand, porin, an Escherichia coli outer membrane protein, retaining its trimeric native structure in the presence of SDS, released a significantly smaller amount of SDS. When the membrane protein was denatured to give a single polypeptide, it behaved in a manner similar to that of the other protein polypeptides. The mechanism of binding of the protein polypeptides was discussed on the basis of these results. The native and denatured entities of porin could be efficiently separated as the result of the difference in their mode of interaction with the hydroxyapatite.

Chromatography↗

Effect of maturation media on male pronucleus formation in pig oocytes matured in vitro.

The present study was carried out to examine the effect of maturation media on male pronucleus formation of pig oocyte matured and fertilized in vitro. Follicular oocytes collected from prepubertal gilts at a local slaughter house were cultured (36 h) in three different media (mTCM-199, Waymouth MB 752/l, and mTLP-PVA), fertilized in vitro, and assessed for nuclear maturation and male pronucleus formation. The addition of 10% (v/v) pig follicular fluid (pFF) to maturation media significantly increased the rate of nuclear maturation of pig oocytes (P less than 0.01), whereas the rate of nuclear maturation of pig oocytes among three different media did not differ. However, the rate of male pronucleus formation of pig oocytes was significantly higher in pig oocytes matured in Waymouth MB 752/l with or without pFF than in oocytes matured in the other two media (P less than 0.01). In experiment 2, the addition of cysteine (the same concentration as in Waymouth medium, 0.57 mM), to mTLP-PVA significantly increased the rate of male pronucleus formation of pig oocytes compared with the control (P less than 0.01). The results indicate that the composition of maturation medium affects the ability of pig oocytes to form male pronuclei following sperm penetration; media containing a high concentration of cysteine (possibly as a substrate of glutathione), such as Waymouth MB 752/l, can remarkably promote this ability.

Animals↗

Evaluation of the pathogenicity and immunogenicity of vaccinia virus to piglets.

The pathogenicity and immunogenicity of vaccinia virus were examined in order to evaluate the possibility of its application as a recombinant viral vaccine in pigs. Following scarification inoculation with vaccinia virus, a mild reddish papulation developed only on the scarified part of the skin. No symptoms of illness such as fever or stunting were noted. Vaccinia virus was recovered in titers from scarified skin 4 and 7 days after inoculation. Control piglets cohabited with inoculated animals remained normal for the whole 5 week observation period. Hemagglutination inhibition and indirect immunofluorescence tests detected antibodies against vaccinia virus in the inoculated piglets, whereas no anti-vaccinia virus antibodies were detected in the contact control animals. Antigen-induced blastogenic tests of peripheral blood lymphocytes from animals, revealed that lymphocytes obtained from inoculated donors 5 weeks after inoculation, had a higher stimulation index (P less than 0.05) than did those from uninoculated piglets. These results suggested that vaccinia virus would be useful as a recombinant viral vector for pigs.

Animals↗